[SOLVED] PWM (4PIN) PST FAN with PWM NON-PST FAN? Need help

Shantanu Mukherji

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Hello,

My Motherboard is an old Intel 67BL which only have two PWM (4PIN) fan ports, one for the back, & another one in front.

I already have two Corsair ML140 140mm PWM (4PIN) Fans that am using in my PC case/cabinet

Now, in order to create a 5 PWM PST fans Daisy chain, can I connect my two Corsair ML140 MM PWM (NON-PST) FAN with my three Arctic P14 PWM PST CO 140MM FAN?

If yes then what should be the order?
 
Solution
Pwm fans don't work from an rpm basis. They work on a duty-cycle. Pwm is pulse width modulation, the pulse is an on/off state. The longer the pulse is on, the faster the fan spins, so in affect what you get is a fan that's always trying to run at maximum speed, but does not get there unless you set the fan to max, which is infinite on pulse.

So the motherboard sensor says to the cpu, 'hey I'm getting warm, fans at 30%'. Cpu says 'OK, let's bump that up a little' and kicks the header to 50% of max. So it really doesn't matter what mix of fans or rpms you use, they are all running at 50%, whether that's at 500rpm for a 1000rpm fan, or 750rpm for a 1500rpm fan.

Yes, for the sake of aesthetics, I'd use the 3x Arctic as exhaust and use a...

Paperdoc

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From an electtrical standpoint there is no problem. the limit really is in the connector hardware resources. The unique feature of those Artic fan models is that they have an extra male connecotor on their wires. So each time you plug one fan's female into a male source, that male source connector is "replaced"with another, and you can build a "daisy-chain" of fans from a single mobo header. However, your older Corsair models, like most, do not have that extra, so using that in a chain must END the chain. Thus, you should connect in two cahains, one from each mobo header, and each chain with an older Corair fan on the end.
 

Shantanu Mukherji

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Jan 26, 2015
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From an electtrical standpoint there is no problem. the limit really is in the connector hardware resources. The unique feature of those Artic fan models is that they have an extra male connecotor on their wires. So each time you plug one fan's female into a male source, that male source connector is "replaced"with another, and you can build a "daisy-chain" of fans from a single mobo header. However, your older Corsair models, like most, do not have that extra, so using that in a chain must END the chain. Thus, you should connect in two cahains, one from each mobo header, and each chain with an older Corair fan on the end.
hi,
Yes, I already thought just like the way you mentioned/described the process here from a generic POC, still, asked here for any other expert opinion,
Anyway, I'll try this after getting those new arctic fans, thanks for replying.
 

Shantanu Mukherji

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Jan 26, 2015
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18,510
From an electtrical standpoint there is no problem. the limit really is in the connector hardware resources. The unique feature of those Artic fan models is that they have an extra male connecotor on their wires. So each time you plug one fan's female into a male source, that male source connector is "replaced"with another, and you can build a "daisy-chain" of fans from a single mobo header. However, your older Corsair models, like most, do not have that extra, so using that in a chain must END the chain. Thus, you should connect in two cahains, one from each mobo header, and each chain with an older Corair fan on the end.
here's the full story for you so that you can suggest me the best.

Here is the link for corsair ML140 140mm PWM Premium Magnetic Levitation Fan — Twin Pack technical specification, & as per this specs sheet, these fans are having an RPM range from 400 - 2000 RPM, so IDK from where did you get & quote that 400-1200 RPM range, & from this RPM factor, these 2 corsair fans are higher than the Arctic. P14 PWM PST

Now coming to the FAN placement & dai Chaine schematics, now I have 2 Corsair MF140MM+2 Artctice P14 PWM PST 140mm Fans+1 Arctic P12 PWM PST CO 120MM FAN. 5 Fans in total, 4 140mm for front & top, one 120mm for back.

MY Case is Gigabite C200 & am planning to install these fans in the following way
  1. Two 140mm P14 PWM PST arctic FANS are in the front
  2. Two Corsair MF140mm PWM fans are at the top
  3. One Arctic 120mm PWM PST CO at the back.

& I will make two PST Daisy Chain,
The first PST aisy chain would be from the Intel DH67BL motherboard's front FAN header with 2 front P14 PWM PSt 140mm fans+1 corsair MF140mm fan at the top, where one Arctic P14 PWM PST 140mm Fan will be connected primarily on the motherboard front fan header, & other two fans will be connected with that fan via PST socket.

And the second PST aisy chain would be from the Intel DH67BL motherboard's backside FAN header, where the P12 PWM PST 120mm Arctic FAn will be connected on motherboard primarily, & the other corsair MF140 MM fan at the top will be connected with that Arctic 120mm PWM PST fan via arctic's PST FAN header.

I hope this would be the correct schematic for my case considering the peripherals (mobo+fans+case) that I have. & by creating two separate daisy chain in this way, the max ampere limit would not be reached for the motherboard fan headers for each daisy chain, as you suggested in your earlier comment.

Let me know what do you think
 

Karadjgne

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I'd not run the fans that way, but that's a personal thing. You have 2 fan headers and 2 zones. Intake and exhaust. They almost never coincide with duty cycles unless at max. The motherboard might decide you need more fan speed from the exhaust sensor header or less from the intake header sensor.

So that's how I'd set the fans up, not a mix and match. The top fans and rear on a 3way splitter to the rear header as exhaust and the 2x Arctic in daisy chain on the front header as intake.

That way each zone responds correctly to its header sensor.
 

Shantanu Mukherji

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Jan 26, 2015
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I'd not run the fans that way, but that's a personal thing. You have 2 fan headers and 2 zones. Intake and exhaust. They almost never coincide with duty cycles unless at max. The motherboard might decide you need more fan speed from the exhaust sensor header or less from the intake header sensor.

So that's how I'd set the fans up, not a mix and match. The top fans and rear on a 3way splitter to the rear header as exhaust and the 2x Arctic in daisy chain on the front header as intake.

That way each zone responds correctly to its header sensor.
yes, you have a valid point here I can see that, then I would install the two Corsair MF140 140mm fans in front for intake without creating a daisy chain as those fans ain't supported PST, & for exhaust in back & top, I will create a daisy chain in between those 3 Arctic fans, & place 120mm fan at back & 2 140mm fans at the top.

What about this way?
 

Shantanu Mukherji

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Jan 26, 2015
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Yes, that arrangement is just fine. I did not quote any fan speeds. But that really does not matter. The important point with fans is the AIR FLOW rate they deliver, not the speed they run.
No, you surely didn't say or mention anything about the RPM, still, I thought to give you (all) a better perspective here by giving all the relevant details & tech specs in this OP.
 

Karadjgne

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Pwm fans don't work from an rpm basis. They work on a duty-cycle. Pwm is pulse width modulation, the pulse is an on/off state. The longer the pulse is on, the faster the fan spins, so in affect what you get is a fan that's always trying to run at maximum speed, but does not get there unless you set the fan to max, which is infinite on pulse.

So the motherboard sensor says to the cpu, 'hey I'm getting warm, fans at 30%'. Cpu says 'OK, let's bump that up a little' and kicks the header to 50% of max. So it really doesn't matter what mix of fans or rpms you use, they are all running at 50%, whether that's at 500rpm for a 1000rpm fan, or 750rpm for a 1500rpm fan.

Yes, for the sake of aesthetics, I'd use the 3x Arctic as exhaust and use a 2way splitter on the Corsair as intake.

The daisy chain of the Arctic is no different than a splitter built in, honestly nothing more than a sales gimmick, especially when considering any argb/rgb fan already has 2x wires to deal with, a third just becomes extra pain to wire up or hide.
 
Solution